IIR document

Part-load control systems, refrigerant selection and sustainability.


Reefer units on containers and vehicles work most of the time under part-load conditions. The choice of the control method has a large impact on the total equivalent warming impact (TEWI) of the system and this value substantially differs from results of full-load based calculations. The paper investigates, for a number of control strategies and refrigerants, the yearly variation of the system performance COSP. This allows the calculation of the integral yearly TEWI of the alternatives. The sustainability of different part-load options in combination with refrigerant selection is discussed. In terms of sustainability (low TEWI), ammonia and isobutane/propane mixtures appear to be preferable options while carbon dioxide appears a less sustainable refrigerant for these applications, although being more sustainable than HFC-404A. Cylinder unloading gives a very sustainable part-load control, limited by the available steps, while hot-gas by-pass is the least sustainable among the continuously modulating methods.

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  • Original title: Part-load control systems, refrigerant selection and sustainability.
  • Record ID : 2004-2488
  • Languages: English
  • Source: 21st IIR International Congress of Refrigeration: Serving the Needs of Mankind.
  • Publication date: 2003/08/17


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